The existing methods of breaching a wall explosively employ one or more pressure charges or a continuous ring or rectangle of linear shaped charges. Both methods have their disadvantages.
The use of an explosive pressure charge is a brute force approach that requires a relatively large quantity of explosive to breach a hole large enough for a man to crawl through. The quantity of explosive required for a wall of moderate thickness is sufficient to shatter nearby windows, create a blast hazard for nearby personnel and cause some structural damage on weaker structures.
For a continuous linear shaped charge device of sufficient explosive strength and surface area to produce an adequate breach in heavy walls, the dimensions, and usually the weight are excessive for effective portability.